Tesla‘s unrivaled product success in the electric vehicle (EV) market stems from a tightly integrated energy storage strategy dating back to the inception of the company. Custom designed battery packs have always sat at the epicenter of Tesla vehicles, enabling industry-leading driving range alongside blistering acceleration.
But the exact composition of the thousands of lithium-ion cells powering the fleet is not always transparent to owners. Let‘s peel back the mystery surrounding Tesla’s battery technology across current and future vehicle models while demystifying some key terminology along the way.
Lithium-Ion Battery Basics
Unlike gas powered vehicles, electric cars rely on onboard battery packs working in concert with power electronics and electric motors to deliver propulsion. So range, performance and overall vehicle capability start right at the cell level for EVs.
Tesla utilizes standardized cylindrical lithium-ion cells measuring 18mm or 21mm in diameter as their battery building blocks. Thousands of these cells are then physically grouped into modules, and modules are further arranged into a fully assembled battery pack powering the drivetrain and onboard electronics.
Tesla‘s cylindrical lithium-ion cell formats over time
Let’s examine Tesla’s pioneering work in lithium-ion cell format evolution enabling longer range electric vehicles.
18650 Cell Format
The origins of Tesla battery packs go back over a decade to the original Tesla Roadster released in 2008. At the time, the go-to commodity cylindrical lithium-ion cell format was the 18650 size, named for its 18mm diameter and 65.0mm length. Most laptop batteries and early electric vehicles relied on this cell size.
Constructed from a specialized nickel-cobalt aluminum cathode chemistry mated to a graphite anode, 18650 cells balance energy density and manufacturing scale. They can deliver a nominal 3.7V along with excellent lifecycle durability. Cooling tabs integrated onto cells also help shed heat when cells are packed closely together.
All of Tesla’s current and past electric vehicle models leverage the trusted 18650 lithium-ion cell format to some degree, except for the newest Model 3 and Model Y built on a next-generation platform.
2170 Cell Format
In 2017, Tesla in partnership with battery partner Panasonic introduced an upgraded cylindrical lithium-ion cell targeted specifically at electric vehicle demands. The 2170 designation refers to its 21mm diameter and 70mm height, delivering increased capacity over 18650 cells.
Size comparison of Tesla‘s 18650 vs 2170 cell formats
How did Tesla manage to squeeze more range and performance out of basically the same sized cell cylinder? It comes down to breakthroughs in nickel-rich cathode chemistry and optimized packaging only feasible with extreme vertical integration control.
The 2170 battery cell simplifies manufacturing and provides room for future improvements to chemistries or production processes. Tesla’s Gigafactory Nevada has refined 2170 cell output for Model 3 and Model Y platforms with industry-leading quality and cost per kWh metrics.
Let‘s now examine how these cells are deployed across Tesla current and next-generation EV product lineup.
Model S Battery Pack Evolution
Debuting in 2012, the groundbreaking Model S luxury sedan emphasized range, performance and cutting-edge technology never seen before in an electric vehicle. Inside sits one of the most dense, well engineered lithium-ion battery packs on the market utilizing thousands of proven 18650 cells.
The original 85 kWh Model S pack houses 7,104 cells configured into 16 separate battery modules consisting of 444 cells each on average. An intricately designed cooling system snakes between modules and around cells to regulate temperature, critical for safety and longevity. Current 100 kWh Model S packs house closer to 8,256 cells, still relying on the 18650 format.
85 kWh Model S battery pack configuration
Advances in battery management systems and manufacturing expertise now allow Tesla to achieve equivalent 100 kWh capacity with fewer total modules. The new Model S Plaid track-capable variant slims down to just 5 battery modules containing 7,920 cells. Dropping over 35 kg of weight while centralized battery integration likely improves chassis stiffness.
Model 3 Battery Miniaturization
Tesla’s challenge adapting Model S DNA into a smaller premium mass market sedan led directly to innovations in battery size, design, and manufacturing strategy. The Model 3 platform demanded range and performance attributes with half the packaging volume of preceding luxury models.
Engineers conceived an all-new module arrangement using the higher density 2170 lithium-ion cells first developed jointly for Model 3 at Gigafactory Nevada. Ongoing refinements to electrode coatings and cell chemistry unlock unrivaled longevity projections over 500,000 miles.
Current 82 kWh Model 3 battery packs incorporate 4,416 cells wired within just 4 compact modules – far exceeding the energy capacity of early 90 kWh Model S packs taking up twice the physical footprint. Further evidence of Tesla‘s industry-leading expertise in battery systems integration and control.
Model X Packs Massive Capacity
Serving as Tesla’s luxury SUV entry, Model X demands substantial battery capacity to generate up to 348 miles EPA rated driving range and seating for 7 adults.
The state-of-the-art Model X Plaid version consolidates the latest 100 kWh pack technology into just 5 structural battery modules like the updated Model S Plaid. However, battery counts swell to a staggering 8,256 18650 lithium-ion cells – the most of any current Tesla vehicle.
Opulent mass and minivan practicality come at the cost of over a third more battery cells versus smaller sedan platforms. But new Diamond Wire Cutting manufacturing processes helping streamline production of latest generation modules keeps costs lower than earlier 100 kWh packs.
Model Y Leverages 2170 Cell Format
Sharing approximately 75% component commonality with the smaller Model 3 sedan including battery pack design, the popular Model Y crossover SUV strikes an appealing balance blending utility with efficiency.
All Model Y configurations draw power from a standardized 82 kWh battery back engineered around Tesla’s workhorse 2170-format lithium-ion cells first implemented at scale in Model 3. The long-range Dual Motor Model Y houses 4,416 cells separated evenly across 4 modules – comparable to its sedan sibling minus a third row of seats.
Next Generation 4680 Cell Format
Tesla recently unveiled development of an entirely new proprietary 4680 cylindrical cell boasting 5x the energy capacity relative to surface area as the previous 2170 cell size. The 46mm wide format promises to lower $/kWh cost through simplifying manufacturing and reducing inactive materials that don’t store lithium.
New structural 4680 battery packs eschew traditional modules altogether for a bonded cell-to-chassis design eliminating substantial weight and labor. Elon Musk claims the 4680 format could enable a $25,000 USD Tesla model within 3 years as production costs drop exponentially.
The latest Tesla Roadster and Cybertruck models plan to leverage this 4680 cell format pending successful volume production ramp. Gigafactory Texas and Berlin facilities are currently working to integrate 4680 cell output, though delays adapting completely new cell manufacturing techniques have pushed initial volume availability to late 2023 at the earliest.
Tesla Battery Pack Fact Sheet
Model | Battery Capacity | Cell Count* | Cell Format | Charging Speed |
---|---|---|---|---|
Model 3 | 50 – 82 kWh | 2,976 – 4,416 | 2170 | 250 kW Max |
Model S | 85 – 100 kWh | 7,104 – 8,256 | 18650 | 250 kW Max |
Model X | 100 kWh | 8,256 | 18650 | 250 kW Max |
Model Y | up to 82 kWh | 4,416** | 2170 | 250 kW Max |
Roadster | 200 kWh | 6,000+*** | 4680 | 1,000+ kW |
*Estimated cell counts based on battery capacity and known module configuration where published officially. Cell counts not confirmed by Tesla across all models.
**Assuming 4 module x ~1,100 cell design matching capacity of dual motor Model 3.
***Projected cell count for next generation Roadster not yet released or confirmed.
Comparing relative battery capacities and cell counts across Tesla’s model history chronicles the rapid advancements in lithium-ion cell chemistry, packaging, and manufacturing processes – all spearheaded internally rather than relying upon outside cell suppliers. No other automaker comes close to Tesla’s prowess maximizing energy density at volume.
Charging Infrastructure Enables Long Distance Travel
Of course, cutting edge battery technology only unlocks the potential for unmatched real world range and performance. Tesla’s industry-leading Supercharger fast charging infrastructure makes long distance electric travel accessible today.
Over 40,000 Superchargers positioned at convenient highway routes across North America, Europe, and Asia replenish hundreds of miles in under an hour. Advance reservations help predict charging demand load balancing as the Tesla fleet continues expanding rapidly year over year.
Proprietary connectors pump 250 kW peak DC power directly into latest generation battery packs adding up to 200 miles of charge in just 15 minutes. Even maxing out charging speed daily has shown minimal long term battery capacity degradation.
Battery Management Maximizes Range & Lifespan
Sophisticated battery management systems distinctive to Tesla monitor voltage and temperature conditions for charging and discharging thousands of cells simultaneously with microsecond resolution. Actively balancing cell states of charge continually optimizes power delivery and protects against cell damage.
Over-the-air software updates deployed seamlessly to the fleet allows improving range through better efficiency and unlocking additional battery capacity held in reserve. Tesla guarantees retaining at least 70% nominal capacity for 8 years with infinite mile warranty coverage. No other electric vehicle comes close to this battery longevity confidence.
Rigorously validated battery models precisely estimate range remaining and charging times adapting to different environmental conditions and driving styles. Streamlined battery design, manufacturing, thermal management, and digitally controlled management polish every facet of the cell-to-wheel solution.
Cost Savings Through Vertical Integration
Owning the entire supply chain from lithium mining partners through proprietary chemistry cell design down to finished module and pack assembly confers Tesla clear strategic advantages. No other automaker today exhibits the competence to engineer long-range EV platforms from scratch.
Maintaining tight vertical integration control over its industry-leading battery technology development separates Tesla from rival automakers now scrambling to secure sufficient cell supply through complicated joint venture contracts with outside vendors.
Bringing key battery R&D in house reduces per kWh cost substantially while protecting valuable intellectual property like battery management algorithms and novel module structural packaging. The forthcoming 4680 cell format with radical tabless electrode architecture promises further step function improvements if Tesla’s swapping robots scale successfully.
The Takeaway
Delving deeper into battery characteristics across Tesla’s range of EV models reveals meticulous, multi-dimensional optimization at work. No other company balances obsessing over cell chemistry, module layout, thermal properties, production techniques, and advanced digital monitoring into every battery pack.
It’s this relentless co-invention of components, software, and manufacturing processes that allows Tesla to stay firmly in the driver’s seat securing battery supply ahead of booming market demand. Surpassing over 3 terawatt-hours of lithium-ion cells produced annually, Tesla still has only begun electrifying transportation at scale. Judging by the recent Cybertruck and Semi unveilings, this capacity is nowhere near the limit of Musk’s long-term ambitions.